This project will help psychologists and educators better understand the early development of temporal knowledge in normal human infants and children. Adults are highly attuned to forward vs. backward presentations of transformations that can only happen in one temporal direction. For example, a film of liquid pouring, when viewed in reverse, is strikingly anomalous. Adults must have internalized temporally organized representations of how thousands of such transformations normally unfold. However, very little is known about the origins and nature of this sensitivity. The principle investigator's research over the past 7 years has suggested that expectations about the temporal direction of several transformations, such as pouring a liquid or breaking an object, develop between 4 and 17 months. The proposed experiments are intended to add to these findings in a number of ways. First, two studies using special training will shed light on the role of experience in the development of temporal-directional sensitivity. Second, a study with new gravity transformations will test the generality of previously demonstrated preferences. A third issue is the importance of dynamic perceptual features in infants' preferences. By comparing directional preferences to fully visible and partially screened versions of stimuli, we can learn whether infants of a given age can mentally represent these changes or whether it is only the combination of perceptual features that is recognized. Fourth, a study of the judgments of children of about 3 years of age will help us interpret the late developmental trends seen in past studies. Basic information about how children adapt to the temporal features of their world is an important part of understanding their perceptual and cognitive abilities. It is expected to have implication for practitioners who design preschool curricula and early childhood intervention programs.
